As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE, AIRCRAFT WOULD YAW TO LEFT UNCOMMANDED SEVERAL TIMES. MDC INDICATES NO FAULT HISTORIES, FCC DIAGNOSTICS INDICATE YD-SVO IN REPAIR CODES FROM FCC1. SUSPECT AHC NR 1 INVALID INPUT TO FCC1. REPLACED NR 1 AHC (AHRS) REF AMM 34-21-01. OPERATIONAL CHECK GOOD.